L-VALINE TREATMENT IMPROVES CELLULAR MITOCHONDRIAL FUNCTION

Abstract Branched-chain amino acids (BCAAs) are pivotal for the health of the human body. Leucine, isoleucine, and valine, which make up the BCAAs, are α-amino acids that promote skeletal muscle growth and development. Valine is one of the essential BCAAs required for the synthesis of muscle proteins and the support growth of skeletal muscles. Valine also plays a favorable role in enhancing insulin sensitivity, preserving intestinal health, and optimizing lipid metabolism. Considering the relevance of valine in promoting muscle growth and metabolism, we utilized C2C12 skeletal muscle cell line to investigate the role of valine in regulating mitochondrial functions. C2C12 cells grown on physiological normal glucose media (100mg/dL) were used for the experiments. Cells were treated with a 1.0 mM concentration of valine for 24 h. The effect of valine treatment on gene expression of important mitochondrial-related genes such as PGC-1α, and PGC-1β and mitofusin (MFN1, MFN), and mitochondrial fission 1 (Fis 1) was determined. Further, Oroboros oxygraph-O2K high-resolution respirometer was used to analyze the mitochondrial respiration in the intact C2C12 cells after valine treatment. The results showed increased gene expression of PGC-1α, PGC-1β, and mitochondrial fission and fusin genes after treatment with valine. The basal respiration, leak respiration, as well as maximal capacity of mitochondrial ETC (Electron Transport Chain), were also significantly improved after valine treatment. The findings from this study enhance our understanding of valine as an important nutrient to improve mitochondrial function to drive cellular function and biological processes.

Senescence was induced by exposure to ionizing radiation and the senescence phenotype was validated through a rigorous panel of senescence and viability markers.Proliferating and senescent renal epithelial cells were screened with a panel of 8 flavonoids to identify senolytic drugs and their concentrations for selectively killing senescent cells.Targeted MS assays were developed to assess intracellular drug uptake, a potential mechanism of senescent-specific killing.To identify protein targets of the senolytic flavonoids in senescent cells, we performed a variation of TPP in combination with liquid chromatography (LC)-MS/MS proteomics analysis, carefully controlling for non-senolytic interactions by excluding proteins bound by a non-senolytic flavonoid.The results of this study pave the way for the development of a more specific generation of senolytic compounds and identify novel candidate senolytic pathways engaged by dietary flavonoids.

LIVING LONGER WITH MODERATE AMOUNTS OF OXYGEN RADICALS IN FRUIT FLIES
Man Su Kim, and Saurav Ghimire, Inje University, Gimhae,

Republic of Korea
The role of reactive oxygen species (ROS) in aging is complex and paradoxical.While the free radical theory of aging suggests that ROS cause cellular damage and senescence, some studies have shown that moderate ROS levels can enhance cellular adaptation and longevity.In this research, we used Drosophila as an in vivo model to investigate the optimal level of ROS that can promote healthy aging.We exposed flies to different concentrations of paraquat (PQ), a herbicide that generates superoxide anions, and measured their lifespan, stress resistance, and gene expression.We found that intermediate PQ levels (0.1 mM) extended lifespan and improved stress tolerance, while high PQ levels (0.5 mM) shortened lifespan and impaired stress response.We also observed an up-regulation of ROS scavenger genes, such as superoxide dismutase 1 and glutathione peroxidase, in the intermediate PQ group, suggesting a homeostatic mechanism to balance ROS levels.Our findings challenge the conventional view of ROS as harmful agents and provide novel insights into the molecular mechanisms of aging.

L-VALINE TREATMENT IMPROVES CELLULAR MITOCHONDRIAL FUNCTION Shakshi Sharma, Gohar Azhar, Xiaomin Zhang, and Jeanne Wei, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
Branched-chain amino acids (BCAAs) are pivotal for the health of the human body.Leucine, isoleucine, and valine, which make up the BCAAs, are α-amino acids that promote skeletal muscle growth and development.Valine is one of the essential BCAAs required for the synthesis of muscle proteins and the support growth of skeletal muscles.Valine also plays a favorable role in enhancing insulin sensitivity, preserving intestinal health, and optimizing lipid metabolism.Considering the relevance of valine in promoting muscle growth and metabolism, we utilized C2C12 skeletal muscle cell line to investigate the role of valine in regulating mitochondrial functions.C2C12 cells grown on physiological normal glucose media (100mg/dL) were used for the experiments.Cells were treated with a 1.0 mM concentration of valine for 24 h.The effect of valine treatment on gene expression of important mitochondrial-related genes such as PGC-1α, and PGC-1β and mitofusin (MFN1, MFN), and mitochondrial fission 1 (Fis 1) was determined.Further, Oroboros oxygraph-O2K high-resolution respirometer was used to analyze the mitochondrial respiration in the intact C2C12 cells after valine treatment.The results showed increased gene expression of PGC-1α, PGC-1β, and mitochondrial fission and fusin genes after treatment with valine.The basal respiration, leak respiration, as well as maximal capacity of mitochondrial ETC (Electron Transport Chain), were also significantly improved after valine treatment.The findings from this study enhance our understanding of valine as an important nutrient to improve mitochondrial function to drive cellular function and biological processes.
Abstract citation ID: igad104.3000Aging is associated with dysregulation of molecular, cellular, and physiological processes.Nutritional and pharmacological interventions with different postulated modes of action have been shown to extend lifespan and delay aging-related diseases in model organisms, suggesting the existence of core cellular processes that mediate the effect on lifespan and healthspan.However, these underlying molecular processes remain largely uncharacterized.In this study, we analyzed multiomic tissue-derived data of lifespan-extending interventions in mice including metabolomics and proteomics from the NIA Longevity Consortium and previously reported transcriptomics.We applied three systems techniques, differential rank conservation (DIRAC) analysis, weighted gene co-expression network analysis (WGCNA), and mouse genome-scale metabolic model (GEM) reconstruction, to the mouse liver proteomic and transcriptomic datasets of lifespanextending interventions (e.g., acarbose, 17α-estradiol, and rapamycin).We found that these interventions generally strengthen the rank conservation of biological processes and shift metabolic fluxes, with fatty acid metabolism emerging as a common process affected by multiple interventions.We then applied these approaches to an expanded experimental data with additional interventions (e.g., canagliflozin) and tissues (e.g., kidney, muscle, and plasma), confirming our results and further observing varied inter-omic and inter-tissue patterns exerted by lifespan-extending interventions.Our findings highlight the potential of integrative systems analysis to elucidate common and unique cellular and physiological changes relating to aging and lifespan-extending interventions, which have translational potential as preventive and prognostic measures to improve human health.

MULTIOMIC SYSTEMS ANALYSIS OF LIFESPAN-EXTENDING INTERVENTIONS IN MOUSE TISSUES
Abstract citation ID: igad104.3001

SEROTONIN AND DOPAMINE CIRCUITS MODULATE AGING IN RESPONSE TO FOOD CUES AND AVAILABILITY
Scott Leiser, University of Michigan, Ann Arbor, Michigan, United States An organism's ability to perceive and respond to changes in its environment is crucial for its health and survival.Multiple studies have shown that modifying this perception through genetic or environmental alterations can extend or shorten lifespan cell non autonomously.These results provide the rationale for identifying "longevity circuits" that could be used to extend healthspan and lifespan by using these signaling pathways.Here we reveal how the most well-studied longevity intervention, dietary restriction, acts in-part through a cell non-autonomous signaling pathway that is inhibited by the presence of multiple food cues.Using an intestinal reporter for a key gene induced by dietary restriction but suppressed by attractive food cues, we identify three compounds that block food cue effects in C. elegans, thereby increasing longevity as dietary restriction mimetics.These compounds and our additional data clearly implicate serotonin and dopamine circuits in limiting lifespan in response to food cues.We further identify multiple neurons, receptors and downstream signals within these circuits.Aspects of these pathways are conserved in D. melanogaster, suggesting at least some "longevity circuits" are conserved.Together, our results show that modulating food cue signaling through serotonin or dopamine circuits is a plausible approach to mimic the benefits of dietary restriction.Altered mitochondrial metabolism is one of the major hallmarks of aging.Notably, age is the biggest risk factor for numerous cancers.Studies suggest that cancer cells shift from anaerobic respiration to oxidative phosphorylation for increasing energy needs.Therefore, this upregulation is a vulnerability that can be targeted using Rho/MRTF/SRF inhibitors.Recent advancement identified a novel series of oxadiazole-thioether compounds that disrupt the SRF transcription.Among those compounds CCG-203971 and CCG-232601 are most metabolic stable, soluble and have no toxicity.They have been shown efficacious in multiple animal models of acute fibrosis, including scleroderma.However, the direct molecular target of these compounds is unclear.Therefore, we investigated the molecular mechanisms of these inhibitors transcription mediated by RhoA which modulates actin dynamics to induce the nuclear accumulation of Myocardin-Related Transcription Factors and their activation of SRF/p49.Our findings suggest that, CCG-203971 and CCG-232601, inhibit Rho/ Kengo Watanabe 1 , Tomasz Wilmanski 1 , Priyanka Baloni 2 , Max Robinson 1 , Oliver Fiehn 3 , Robert Moritz 1 , Richard Miller 4 , and Noa Rappaport 1 , 1. Institute for Systems Biology, Seattle, Washington, United States, 2. Purdue University, West Lafayette, Indiana, United States, 3. UC Davis, Davis, California, United States, 4. University of Michigan, Ann Arbor, Michigan, United States